Feeding mechanism for rock drills



FEEDING MECHANISM PQR ROCK DRILLS Filed June '7Q 1923 Z f JQH l F o w l i 1 l /l H I YZ e I m 12 I@ i? FE l mrd@ R" @4E n/l l INVENTOR H ATTORNEY Patented Apr. 7, 1925.

\ Unirse y.STAT-ges.

'PlAi-r nur orifice anni) ivi, sLAtrEn, oFnAs'rloN, PENNSYLYANIA, AssIGNon To insensata-aaien CoMPANY., or JERSEY crrY, NEW mesnil., A Cnronarrolv =`oar FEEDING MECHANISM' FOR ROCKDRTLLS.

Application filled June *7,

To LZ/Z whom if may coi/Lemmi.'

Be it known that I, Fimo M. Snaren, a citizen of the United States, and a: resident of Easton, county of Northampton, ,and State of Pennsylvania, have invented a certain Feeding Mechanism for Rock Drills, of which the following is a specification ac-' companied by drawings.

rIhis invention relates to rock drills, but more particularly to the feeding means of a stope drill, and is in some respects an improvement upon the feeding means shown and described in the co-pending application of Harry V. I-Iaight, Serial No. 649,083 filed July 2, 1923, to which I have permission to reiter.

rlhe object of the invention is to enable [the packing in the feed piston to be tightly pressed against the feed cylinder, in accordance with the pressure in the cylinder, so that it always remains tight and this is accomplished in an improved and simpli-v fied manner.

Another object of the invention is to produce an improved means for holding the said feed piston having a self tightening packing in its eXtreme inward position in the feed cylinder.

Further objects of the invention will hereinafter appear, and to all of these ends the invention is shown in one of its preferred forms in thel accompanying drawings, in which Figure l is a side elevation partly in vertical section of a stope drill embodying the invention, which may be taken as an illustrative example.

Figure 2 is an enlarged fragmentary vertical sectional view in detail of the feed piston,

Figure 3 is a transverse section taken on the line 3 3 of Figure 2, looking in the direction of the arrows, and

Figure 4 is a detail perspective view of the split spring ring. i

Referring to the drawings, the stope drill has a cylinder A to which is secured the front head B by the usual side bolts C, and in which front head the drill steel D eX- tends for receiving the impact blows of the hammer piston. The cylinder A is separated from the feed cylinder E by the head block F, to which is secured the usual rotation handle G for manually rotating the drill steel D. Motive fluid is admitted to 1f928. Seriali' N-O. 643,838;

the machine through the inlet I-I and is controlled by a throttle valve, having the handle In accordance with this invention, the "iieed'A piston K comprises the capii and main head O. The cap L is adapted to have limited longitudinal movement in the main head O and the body portion of the cap is guided in the cup shaped cavity by the walls of the head. The cap L is. formed with a recess P and an integral guiding projection or tongue Q, having a slot R adjacent the end thereof. Located between the main head O and the cap L is a packing S, which may be of a long fiber braided asbestos or any other material. The packing S is adapted to be pressed tightly against the feed cylinder E by the cap L, so that the greater the pressure within the feed cylinder, the more tightly will the packing be pressed against the cylinder.

In this instance, a piston rod T is formed integral with the main head O and carries the usual rock engaging pointer U at its lower end. For limiting the movement of the cap L, a pin V is inserted in the piston rod T, and passes through the slot R in the tongue Q and a cotter pin W located in the groove X in the piston rod, prevents the pin from coming loose.

A feed cylinder bushing Y is formed with a port Z for admitting pressure fluid to the feed cylinder E. A threaded p-rojection a on the bushing Y carries a retainer member in the form of a nut for holding the split metallic ring c, which is adapted to enter the recess P in the cap L for frictionally holding the piston K in its extreme inward position in the feed cylinder, so that the drill may be conveniently carried without the piston rod T moving outwardly in the cylinder.

The cap L is preferably cylindrical and is adapted to slide within a bore in the cup shaped main head O. lAt the upper end of the cap L there is provided a flange which with the cylindrical surface of the head O and the inner surface of the cylinder E forms an annular recess of rec- -tangular cross section for the insertion of the packing material S. As the cap L is pressed into the head O this flange squeezes the packing material S against the cylinder walls and against the cylindrical surface of the cap L.

iti() ics In devices of this sort the airis apt to leal: under the cap and exert pressure on its under side which tends to equalize the pressure on the upper face. This is avoided in this construction since the packing material S is adapted to be squeezed against the cylindrical surface of the cap to prevent leakage to the lower faces. A relatively great, pressure is therefore assured on the upper face of the cap L for pressing the packing S.

I claim:

A Huid pressure piston, comprising a cup shaped main hollow piston head, a hollow Cylindrical cap having limited longitudinal movement in said hollow head, the hody portion of said cap being guided in the head cavity by the walls of the head, said cap having a lange at its outer end, packing material in the recess Yformed between the said cap flange and the main head, and a guiding projection formed integral with they cap and extending inwardly from the body portion of the cap into the main piston head, and means for limiting the longitudinal movement of the guiding projection and cap relatively to the main piston head.

In testimony whereof I have signed this specification.

FRED M. SLATER. 

